UnicodeDecodeError traceback on URL preview

[matrixbot]

This issue has been migrated from #4585.

---

Description

UnicodeDecodeError

Steps to reproduce

synapse.http.server - 112 - ERROR - GET-132- Failed handle request via <function PreviewUrlResource._async_render_GET at 0x7fd5271cd2f0>: <XForwardedForRequest at 0x7fd525a65da0 method='GET' uri='/_matrix/media/r0/preview_url?url=http%3A%2F%2Fwww.sirkusaikamoinen.com%2Ffutureperformances%2Fnomad-i-mariagrdens-kyrkosal-i-borg%E2%80%8B&ts=1539766933898' clientproto='HTTP/1.1' site=8008>: Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1418, in _inlineCallbacks
    result = g.send(result)
  File "/usr/local/lib/python3.6/site-packages/synapse/http/server.py", line 81, in wrapped_request_handler
    yield h(self, request)
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1613, in unwindGenerator
    return _cancellableInlineCallbacks(gen)
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1529, in _cancellableInlineCallbacks
    _inlineCallbacks(None, g, status)
--- <exception caught here> ---
  File "/usr/local/lib/python3.6/site-packages/synapse/http/server.py", line 81, in wrapped_request_handler
    yield h(self, request)
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1418, in _inlineCallbacks
    result = g.send(result)
  File "/usr/local/lib/python3.6/site-packages/synapse/rest/media/v1/preview_url_resource.py", line 110, in _async_render_GET
    url = parse_string(request, "url")
  File "/usr/local/lib/python3.6/site-packages/synapse/http/servlet.py", line 144, in parse_string
    request.args, name, default, required, allowed_values, param_type, encoding
  File "/usr/local/lib/python3.6/site-packages/synapse/http/servlet.py", line 158, in parse_string_from_args
    value = value.decode(encoding)
builtins.UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 86: ordinal not in range(128)
synapse.http.server - 112 - ERROR - GET-134- Failed handle request via <function PreviewUrlResource._async_render_GET at 0x7fd5271cd2f0>: <XForwardedForRequest at 0x7fd525e9a748 method='GET' uri='/_matrix/media/r0/preview_url?url=http%3A%2F%2Fwww.haaganpuro.fi%2Fajankohtaista%2Fr-i-p-pirkko%2F%E2%80%8B&ts=1539852446322' clientproto='HTTP/1.1' site=8008>: Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1418, in _inlineCallbacks
    result = g.send(result)
  File "/usr/local/lib/python3.6/site-packages/synapse/http/server.py", line 81, in wrapped_request_handler
    yield h(self, request)
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1613, in unwindGenerator
    return _cancellableInlineCallbacks(gen)
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1529, in _cancellableInlineCallbacks
    _inlineCallbacks(None, g, status)
--- <exception caught here> ---
  File "/usr/local/lib/python3.6/site-packages/synapse/http/server.py", line 81, in wrapped_request_handler
    yield h(self, request)
  File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1418, in _inlineCallbacks
    result = g.send(result)
  File "/usr/local/lib/python3.6/site-packages/synapse/rest/media/v1/preview_url_resource.py", line 110, in _async_render_GET
    url = parse_string(request, "url")
  File "/usr/local/lib/python3.6/site-packages/synapse/http/servlet.py", line 144, in parse_string
    request.args, name, default, required, allowed_values, param_type, encoding
  File "/usr/local/lib/python3.6/site-packages/synapse/http/servlet.py", line 158, in parse_string_from_args
    value = value.decode(encoding)
builtins.UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 52: ordinal not in range(128)

Version information

• Version: 0.99.0
• Install method: docker
• Platform: Linux